"Current saver"? What is that? My Mez has some additional circuitry powered off the 12V regulator, but I'm sure the power dissipation is still low enough it doesn't need a heat sink. That didn't stop me using one.
Pretty much any time I use a TO-5 regulator I stick a heat sink on it. Needed? Usually not. But I do it anyway because it "feels" right.
Help! The 5-led string on the IRFP240 side won't light.
I finished populating the Hypno pcb and in the end I made a grave mistake: I swapped the IRFP240 and IRFP9240s. Then, I was getting something like +0.6V and -1.89V at the o/p. Re-read the thread and realised my mistake. Unsoldered the 4 IRFs and put them in correctly.
The 5-led string on the 240 side did not light. Measured the o/p and I got +10.12V and -19V. Today I bought a new 240 and still the leds don't light. I don't understand SS electronics but it seems the original 240 was OK and the problem is somewhere else.
In order not to start pulling out components haphazardly can someone please guide me what to check? There is the schematic for the -ve supply at post# 874 (but as I said I'm not able to interpret it).
Thanks and regards.
I finished populating the Hypno pcb and in the end I made a grave mistake: I swapped the IRFP240 and IRFP9240s. Then, I was getting something like +0.6V and -1.89V at the o/p. Re-read the thread and realised my mistake. Unsoldered the 4 IRFs and put them in correctly.
The 5-led string on the 240 side did not light. Measured the o/p and I got +10.12V and -19V. Today I bought a new 240 and still the leds don't light. I don't understand SS electronics but it seems the original 240 was OK and the problem is somewhere else.
In order not to start pulling out components haphazardly can someone please guide me what to check? There is the schematic for the -ve supply at post# 874 (but as I said I'm not able to interpret it).
Thanks and regards.
Current saver = A resistor and capacitor added to the relay coil.
The resistor is added in series with the coil on the opposite side to the switching transistor.
The capacitor is added in parallel to the series combination of coil and switching transistor.
Prior to the transistor going to ON, the cap charges to the voltage sent by the supply, up to that extra resistor.
When the transistor does switch ON the cap partially discharges through the coil to trigger the relay ON. The resistor then comes into play and feeds a constant but lower voltage to the relay coil. The coil runs cooler. The PSU feeds less current. The relay drops out quicker when going to OFF. And just maybe the over-stroking and relaxation during the cap current pulse cleans the contacts better than the standard "wipe" built into the mechanical mechanism of all relays.
The resistor is added in series with the coil on the opposite side to the switching transistor.
The capacitor is added in parallel to the series combination of coil and switching transistor.
Prior to the transistor going to ON, the cap charges to the voltage sent by the supply, up to that extra resistor.
When the transistor does switch ON the cap partially discharges through the coil to trigger the relay ON. The resistor then comes into play and feeds a constant but lower voltage to the relay coil. The coil runs cooler. The PSU feeds less current. The relay drops out quicker when going to OFF. And just maybe the over-stroking and relaxation during the cap current pulse cleans the contacts better than the standard "wipe" built into the mechanical mechanism of all relays.
I'm seriously considering eliminating the adjustment pots altogether and doing the room adjustment using the player's electronic level controls. Andrew T's suggestion of buffered pots makes sense, except for the fact that I'm putting all this effort & expense into building a nice buffer, and then I'd be putting a cheesy op-amp buffer in front of it! I'll just have to try it, I suppose - it's the only way to know for sure whether it would make a difference.
One problem is that according to the settings spit out by the automated setup procedure in my current A/V preamp (Sherwood Newcastle) the sub/LFE channel is +10dB (or more - I forget) over the mains. Of course there's no gain possible in the Hypnotize, so the mains would have to be attenuated 10dB - and if I really want to shake the walls (and I do occasionally) I might not have much of a maximum volume available. With the electronic controls I can actually boost the sub channel. I guess I won't know for sure about that either until I try it.
That would ameliorate the level problem, but I'd have to find room in the case for a gain module, and that would be tricky - not to mention fitting in another power supply! The surrounds are about +5dB, but that's not so much of a problem. As far as real estate goes, I also want to fit in a headphone amp for the sake of convenience (with the main channels switchable to the headphone amp input) and I was hoping to squeeze a PPA board in......might have to do with an A47 instead.
Ha - another thought - I'll have to see if the power amp I'm using for the sub has a level control in the back - it might......
Sorry if this seems a little off-topic, but this is a hot-rodded DCB1 I'm building, though my hot-rodding will have to be somewhat limited by having three boards in the same box! (I bought a little fan for the back panel!)
Hello Nick,
Your diagnosis is spot-on!!! As always. I get 10.14V and 10.12V at the output which is good. I can also hear a faint click a few seconds after turn on. Now I need to test it at the output of my C-J cd/preamp (output Z <200ohms - is that OK? - I should think so.)
Is it OK if I leave the IRFPs in free air (w/o heatsink) for the test period (max. 1 hour, I hope. I may like it so much as to leave it longer!!)?
If all goes well I intend to purchase/build a Lightspeed for maximum effect.
Thanks again and all the best.
Joe A
Your diagnosis is spot-on!!! As always. I get 10.14V and 10.12V at the output which is good. I can also hear a faint click a few seconds after turn on. Now I need to test it at the output of my C-J cd/preamp (output Z <200ohms - is that OK? - I should think so.)
Is it OK if I leave the IRFPs in free air (w/o heatsink) for the test period (max. 1 hour, I hope. I may like it so much as to leave it longer!!)?
If all goes well I intend to purchase/build a Lightspeed for maximum effect.
Thanks again and all the best.
Joe A
Thanks Tea-Bag.
As I said, I used the pcb and kit which you so generously organised. The indications on top the pcb make it very easy even for beginners to populate the board. There is always the risk of fitting a component or two the wrong way round, as happened to me! That was probably due to my eagerness to see it working.
Anyway, thanks all who contributed to a fun project like this: Salas (above all), CRT, Nelson, you and all who contribute/d to this project. Still have to hear it and I hope to report on my findings.
Best regards,
Joe A
As I said, I used the pcb and kit which you so generously organised. The indications on top the pcb make it very easy even for beginners to populate the board. There is always the risk of fitting a component or two the wrong way round, as happened to me! That was probably due to my eagerness to see it working.
Anyway, thanks all who contributed to a fun project like this: Salas (above all), CRT, Nelson, you and all who contribute/d to this project. Still have to hear it and I hope to report on my findings.
Best regards,
Joe A
It's actually for a red one. I took the 2k2 out and put a 10k and that wasn't enough. I added a 27.4k in series to the 10k and that was about perfect. It's on an led panel mounter on the front panel and it's REALLY bright with the 2k2. Thanks Salas.
Finished
Finished my cap testing, kept the Black Gate STD, which finally sounded great after well over 200 hours of break-in. Their imaging and definition was the best of the lot, but I still find them sounding a bit bright. I would rank Slimic II as second best.
The finished thing has a Chinese rcore, the cheap Udailey LDR board with a small Dantimax ps, a Dantimax remote volume controller for the LDR board, silver wire in oversize teflon sleeves for the input/ouput and the input is routed through a Glassware 3 position selector switch. TX2575s for the 220R and 220K, Caddocks for the 1M, 2.5R Mills. I can still put my hand on the heatsinks for longer than 5 seconds.
Last upgrade I'm contemplating is replacing the 4700uF ps caps for Mundorfs...
I'm very happy with the sound. Thanks again for all the help building it.
Finished my cap testing, kept the Black Gate STD, which finally sounded great after well over 200 hours of break-in. Their imaging and definition was the best of the lot, but I still find them sounding a bit bright. I would rank Slimic II as second best.
The finished thing has a Chinese rcore, the cheap Udailey LDR board with a small Dantimax ps, a Dantimax remote volume controller for the LDR board, silver wire in oversize teflon sleeves for the input/ouput and the input is routed through a Glassware 3 position selector switch. TX2575s for the 220R and 220K, Caddocks for the 1M, 2.5R Mills. I can still put my hand on the heatsinks for longer than 5 seconds.
Last upgrade I'm contemplating is replacing the 4700uF ps caps for Mundorfs...
I'm very happy with the sound. Thanks again for all the help building it.
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Nice build. What is the rest of your system?
Thanks Salas.
I have Acoustat 2+2 speakers with a Revel B120 subwoofer (cutting it at 60hz), a PS Audio 200c amp, a modified Behringer DEQ2496 (output stage by-passed with Jensen transformers) and an Audio Widget for dacs and a currently armless VPI HW-19 turntable (looking for an Ittok arm for it). 99% of my music is in flacs in a computer which feeds the audio widget dac by usb and the Berhinger from spdif, using mpd in linux.
I have Acoustat 2+2 speakers with a Revel B120 subwoofer (cutting it at 60hz), a PS Audio 200c amp, a modified Behringer DEQ2496 (output stage by-passed with Jensen transformers) and an Audio Widget for dacs and a currently armless VPI HW-19 turntable (looking for an Ittok arm for it). 99% of my music is in flacs in a computer which feeds the audio widget dac by usb and the Berhinger from spdif, using mpd in linux.